Nereus

And going on foot through Illyria and hastening to the river Eridanus he came to the nymphs, the daughters of Zeus and Themis. They revealed Nereus to him, and Hercules seized him while he slept, and though the god turned himself into all kinds of shapes, the hero bound him and did not release him till he had learned from him where were the apples and the Hesperides. Being informed, he traversed Libya. That country was then ruled by Antaeus, son of Poseidon, who used to kill strangers by forcing them to wrestle.


- Apollodorus, Library, Book 2, Chapter 5, Section 11